This invention relates to production of stator coils for dynamo-electric machines. More particularly, this invention relates to production of stator coils in which the initial and final leads of each coil are connected to final attachment points before the coils are inserted into a stator core.
Conventionally, a stator coil is wound on a template by a rotating flyer arm through which coil wire is delivered. The coil is then transferred from the template to a coil-holding tool, which may be a transfer tool or a coil insertion tool. Both include a series of upright members circumferentially positioned on the base of the tool. The sides of each coil are placed in the spacings between predetermined upright members. Optionally, coil leads can be temporarily anchored to a retaining or anchoring device to later facilitate lead identification.
If the coil-holding tool is a transfer tool, the coils are transferred to a coil insertion tool typically located at an insertion station. The upright members of the coil insertion tool are commonly regularly-spaced insertion blades. A stator core is positioned on top of the insertion blades with the stator slots into which the coils are to be inserted aligned with the spacings containing the coils. A pusher device then transfers the coils from the insertion tool to their final positions within the stator slots. The pusher device typically also inserts wedges into the stator slots to cover the coils.
Each coil has an initial and final lead. After insertion of typically many coils into a stator core, each lead of each coil is individually identified and manipulated for connection to a final attachment point. In those cases where leads are not temporarily anchored, lead identification can be particularly difficult considering the typically dozens of dangling and often entangled coil leads associated with most stators. Lead manipulation can include routing a lead to a particular attachment point, such as, for example, a wire socket of a terminal receiver or a connection to another coil lead, where the two leads are usually crimped with an insulating sleeve. Typically, coil leads are routed by running them along the end portions of the coil from which they originate. Lead manipulation can also include lacing leads around end portions of coils to fix the positions of the leads for later internal or external stator connections. Lead manipulation can further include bundling several identified leads together and then soldering them to form a single lead connection point. After the coil leads are connected to their final attachment points, connections to electrical conductors or components external to the stator are usually made.
These post-coil-insertion processes (i.e., lead identification and manipulation) are often performed manually or, if coil leads are temporarily anchored (which facilitates lead identification), these processes are sometimes performed automatically. In either case, lead identification and manipulation processes are time-consuming, often inefficient (particularly when performed manually), and usually require additional equipment or machinery and additional processing steps (particularly when performed automatically).
In view of the foregoing, it would be desirable to improve the efficiency of stator production by producing stator coils having leads automatically connected to final attachment points before the coils are inserted into a stator core.
It is an object of this invention to improve the efficiency of stator production by producing stator coils having leads automatically connected to final attachment points before the coils are inserted into a stator core.
In accordance with this invention, methods and apparatus are provided that connect multiple wire leads of multiple coils to one or more devices comprising final attachment points of the leads before the coils are inserted into a stator core. Apparatus includes coil winding apparatus, a coil-holding tool, a platform for supporting the coil-holding tool, at least one final attachment device, and a lead gripper device that can grasp a wire from the coil winding apparatus and connect it to a final attachment device. Methods include winding a wire to form a coil, connecting a lead of the coil to a final attachment device, loading the coil onto a coil-holding tool, and repeating the above at least once. Coils that have been loaded onto the coil-holding tool are then inserted into a stator core. The transfer of coils from the coil-holding tool to the stator core is direct if the coil-holding tool is a coil insertion tool. Otherwise, the coils are transferred first from the coil-holding tool to a coil insertion tool. Lastly, the final attachment device can be mounted to a stator receiving the stator core. Advantageously, post-coil-insertion lead identification and manipulation are substantially unnecessary. Moreover, the time required to automatically connect wire leads to a final attachment device is substantially the same as or less than the time required in known processes to temporarily anchor leads to an anchoring device. Accordingly, stator production efficiency is improved.